求助:怎样知道.wav文件的频率、位及声道?

[zangyulong01]

怎样知道.wav文件的频率、位及声道?

[fairyprince]

http://jzc1202.blog.163.com/blog/static/9427674200732124616398/

[zkok2005]

试试这个软件cooledit

[zangyulong01]

不是要用软件的,我是想怎样编写出.wav的频率&位及声道

[rageliu]

HRESULT CFrameGrabberDlg::GrabFrameFromMovie()
{
HRESULT hr;
// 定义IMediaDet接口实例
CComPtr< IMediaDet > pDet;
hr = CoCreateInstance( CLSID_MediaDet, NULL, CLSCTX_INPROC_SERVER,
IID_IMediaDet, (void**) &pDet );
if (FAILED(hr))
return hr;

// 将影片文件名转换成BSTR类型
CComBSTR openBSTR(m_editOpenDir);
// 设置IMediaDet接口的文件关联
hr = pDet->put_Filename(openBSTR);
if (FAILED(hr))
return hr;

// 从影片中检索视频流和音频流
long lStreams;
hr = pDet->get_OutputStreams(&lStreams);
if (FAILED(hr))
return hr;

// 取出影片的视频流，因为帧的信息是保存在视频流中的
bool bFound = false;
for (int i=0; i<lStreams; i++)
{
GUID major_type;
hr = pDet->put_CurrentStream(i);
if (SUCCEEDED(hr))
hr = pDet->get_StreamType(&major_type);
if (FAILED(hr))
break;
if (major_type == MEDIATYPE_Video)
{
bFound = true;
break;
}
}
if (!bFound)
return VFW_E_INVALIDMEDIATYPE;

long width = 0, height = 0; // 存储位图的宽和高（单位：象素）
AM_MEDIA_TYPE mt;
hr = pDet->get_StreamMediaType(&mt);
if (SUCCEEDED(hr))
{
if ((mt.formattype == FORMAT_VideoInfo) &&
(mt.cbFormat >= sizeof(VIDEOINFOHEADER)))
{
// 得到VIDEOINFOHEADER结构指针，VIDEOINFOHEADER结构包含一些与视频
// 有关的信息，其中含有BITMAPINFORHEADER结构
VIDEOINFOHEADER *pVih = (VIDEOINFOHEADER*)(mt.pbFormat);
width = pVih->bmiHeader.biWidth;
height = pVih->bmiHeader.biHeight;
}
else
hr = VFW_E_INVALIDMEDIATYPE;
MyFreeMediaType(mt); // 释放AM_MEDIA_TYPE结构
}
if (FAILED(hr))
return hr;

CComBSTR saveBSTR(m_editSaveDir);
// 将第一帧保存为指定路径的位图文件
hr = pDet->WriteBitmapBits(0, width, height, saveBSTR);
if (FAILED(hr))
return hr;

return S_OK;
}

[rageliu]

用DirectShow抓取影片帧的代码，其中一段就是楼主要的了

[DentistryDoctor]

wav文件前面有WAVEFORMATEX结构，直接读出即可。

[bayni_1980]

typedef struct
{
char cID[4];
DWORD dwLen;
char cWID[4];
char cFmt[4];
DWORD dwHead;
WORD wFormatTag;
WORD wChannels;
DWORD dwSamplesPerSec;
DWORD dwAvgBytesPerSec;
WORD wBlockAlign;
WORD wBitsPerSample;
char cDATA[4];
DWORD dwFileSize;
} WAVEHEADER;

[bayni_1980]

可以参考一下MSDN中Windows Multimedia的WAVEFORMAT/WAVEFORMATEX结构体

[taianmonkey]

HMMIO m_hmmio;
MMCKINFO m_MMCkInfoParent;
WAVEFORMATEX m_PCMWaveFmtRecord;
MMCKINFO m_MMCkInfoChild;
/* typedef struct {
WORD wFormatTag;
WORD nChannels;
DWORD nSamplesPerSec;
DWORD nAvgBytesPerSec;
WORD nBlockAlign;
WORD wBitsPerSample;
WORD cbSize;
} WAVEFORMATEX;
*/

TCHAR bigBuff[2048] = ""; // maximum common dialog buffer size
TCHAR szFilter[] =
"Text Files (*.wav)|*.wav|All Files (*.*)|*.*||";
//TCHAR csFileName[MAX_PATH];
//CString csFileName;
CString m_strFilePath;

CString strWaveInformation;
CString szExtFile;

CFileDialog dlg(TRUE, NULL, NULL,
OFN_HIDEREADONLY | OFN_ALLOWMULTISELECT, szFilter);


// Modify OPENFILENAME members directly to point to bigBuff
dlg.m_ofn.lpstrFile = bigBuff;
dlg.m_ofn.nMaxFile = sizeof(bigBuff);

if(dlg.DoModal() == IDOK)
{
m_strFilePath = dlg.GetPathName();
}
else
return;

m_hmmio = mmioOpen((LPSTR)(LPCTSTR)m_strFilePath,NULL,MMIO_READ);
if(!m_hmmio)
{
AfxMessageBox("unable to open Sound MM File");
return ;
}
m_MMCkInfoParent.fccType = mmioFOURCC('W','A','V','E');
int errorCode = mmioDescend(m_hmmio, &m_MMCkInfoParent,NULL,MMIO_FINDRIFF);
if(errorCode)
{
AfxMessageBox("Error descending into file");
mmioClose(m_hmmio,0);
m_hmmio = NULL;
return ;
}
m_MMCkInfoChild.ckid = mmioFOURCC('f','m','t',' ');
errorCode = mmioDescend(m_hmmio,&m_MMCkInfoChild,&m_MMCkInfoParent,MMIO_FINDCHUNK);
if(errorCode)
{
AfxMessageBox("Error descending in file");
mmioClose(m_hmmio,0);
m_hmmio = NULL;
return ;
}
DWORD bytesRead = mmioRead(m_hmmio,(LPSTR)&m_PCMWaveFmtRecord,m_MMCkInfoChild.cksize);
if(bytesRead < 0)
{
AfxMessageBox("Error reading PCM wave format record");
mmioClose(m_hmmio,0);
return ;
}
strWaveInformation.Format("wFormatTag = %d , nChannels = %d, nSamplesPerSec = %d, nAvgBytesPerSec = %d, nBlockAlign = %d, wBitsPerSample = %d, cbSize = %d",
m_PCMWaveFmtRecord.wFormatTag, m_PCMWaveFmtRecord.nChannels,
m_PCMWaveFmtRecord.nSamplesPerSec ,m_PCMWaveFmtRecord.nAvgBytesPerSec ,
m_PCMWaveFmtRecord.nBlockAlign, m_PCMWaveFmtRecord.wBitsPerSample,m_PCMWaveFmtRecord.cbSize);
AfxMessageBox(strWaveInformation);